Wood type golf clubs are used for hitting the ball off the tee, from the fairway, or possibly from the rough or a hazard. The type of golf club chosen by a golfer for a particular shot depends on the shot desired and the condition of the ball's lie. For example, a driver is generally used for tee shots and fairway woods are generally used for hitting the ball from the fairway or rough. A tee shot generally involves hitting the ball from an elevated position and fairway and rough shots involve hitting the ball from the ground. The various functional aspects of the soles of these clubs can be optimized to minimize any deleterious conditions the club head may experience during the swing.
The faster a club head is moving when it comes in contact with the ball, the farther the ball will travel. Any contact with the ground during a swing prior to contact with the ball slows down the speed of the club head and decreases the distance the ball will travel. Further, when a club head strikes an imperfect surface, i.e., the ground, the trajectory of the club head can be altered with deleterious effect on the resultant trajectory of the ball. When striking a ball from an elevated tee, a golfer is generally able to prevent the club head from hitting the ground. However, when striking a ball positioned on the ground, the club head will often strike the ground during the swing. Thus, it is preferred that a club head be optimized for both aerodynamics and to minimize frictional losses to club head speed and alterations to the club head's trajectory caused by ground contact. By maximizing club head speed and minimizing alterations to the club head's trajectory, a true shot may be hit that will travel farther and straighter than otherwise possible.
The deleterious effect that making contact with the ground has on a golf shot often causes golfers to have low confidence as they approach a ball with an imperfect lie. Hitting a ball “fat” or “duffing,” as mentioned above, results in a short and potentially errant shot. The fear of “duffing” often causes golfers to unconsciously pull up during their swing resulting in a “topped” shot, which occurs when only the top portion of the ball is struck. As neither topping nor duffing is desirable, a golf club that minimizes the effects of a duffed shot would enable a golfer to approach a ball with confidence thereby preventing topped shots.